Led driving device for dynamic segment configurations and the led lighting apparatus thereof

ABSTRACT

The invention discloses an LED driving device for dynamic segment configurations and the LED lighting apparatus thereof, wherein, the said LED driving device includes a first adjustable LED lamp string unit, a first N-type switch module, at least one second adjustable LED lamp string unit, one unidirectional conduction unit, one P-type switch module, one second N-type switch module, control logic module and current detection module; the control logic module outputs control signals, based on output voltage changes from the bridge rectifier, to control the on and off states of the first adjustable LED lamp string unit, the adjustable LED lamp string module, the P-type switch module, the first and second N-type switch module, also it adjusts the parallel and serial connection states of the first and second adjustable LED lamp string units dynamically. The invention adopts the dynamically configuring technology, improving the lighting effects and the utilization of LED lamps.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation application of PCT Patent ApplicationPCT/CN2014/081 411, filed on Jul. 1, 2014, which claims priority toChinese Patent Application No. 20131 0327523.2, filed on Jul. 31, 2013,the content of all of which is incorporate herein by reference.

FIELD OF THE INVENTION

The present invention relates to the field of LED lighting technologyarea, and more particularly, to an LED driving device for dynamicsegment configurations and the LED lighting apparatus thereof.

BACKGROUND

In a traditional driving circuit for LED (Light Emitting Diode), afterthe supplied power has passed through a bridge rectifier and has beenconverted into a DC power, generally, it still requires extra processesthrough some electric elements including inductors and electrolyticcapacitors, before driving any LEDs. However, the life of anelectrolytic capacitor is relatively short, which has severelyrestricted the whole life of a driving circuit for LED, also, theconversion efficiency is usually as low as 80%. Thus, it has seriouslyaffected the LED lighting effects.

In order to avoid the use of inductors and capacitors, designers havemade some improvements on the driving circuit for LED, shown as FIG. 1,which is a circuit diagram in the patent of invention with a publicationNo. CN 102196627, wherein, three MOS transistors, 88, 87, 86, areapplied to short-circuit or open-circuit the LED short string 62, LEDshort string 61, or LED short string 60. Take the MOS transistor 87 asan example, when it short-circuits the LED short string 61, the powervoltage between L3 and L4 is close to zero; when it open-circuits theLED short string 61, the power voltage between L3 and L4 is 16N×3.0V(wherein, 3.0V is the power voltage between the two ends of a singleLED, when it is on). Suppose the supplied power voltage is 220V, then,when all LEDs are lit-on, the voltage drop over the LEDs should be closeto the highest voltage output from the bridge rectifier, which is,220×1.414=311V, thus, the total number of LEDs should be around 100, andN should be at least 2. Therefore, when the MOS transistor 87open-circuits the LED short string 61, the power voltage between L3 andL4 is 16N×3.0V>16×2×3.0V=96V. If all LEDs are lit-on, the power voltageof L3 to the ground should be 15×3.0V=45.0V

From the analysis above, it can be seen that, the lowest withstandvoltage from the source of the MOS transistor 87 (connecting to L3) tothe ground is 45V, the lowest withstand voltage from the drain of theMOS transistor 87 (connecting to L4) to the ground is 45+96=141V, whilethe lowest withstand voltage between the drain and the source of astandard MOS transistor 87 is 96V. Also, the driving circuit for thegate of the MOS transistor 87 (connecting to NG4) is also verycomplicated. In current arts for semi-conductor integrations, such a MOStransistor is impossible to be integrated. Therefore, the circuitconfiguration of the driving circuit is particularly complex, therequirements of the withstand voltages for each element are relativelyhigh, and it is difficult to be integrated into one chip, therefore, itdoes not satisfy the increasing miniaturization requirements forelectronic products. Shown as FIG. 2, which is a circuit diagram in thepatent of invention with a publication No. US 2011/0084619A1, wherein,according to the claim 2, it can be seen that, through an AC(alternating current) synchronous circuit, different LED light stringsare selected to be turned on at different time points, and the currentsin the LED lamp strings are adjusted according to time. When drivingLEDs, shutting 12B off and 12C on at a certain time point, the number ofLEDs gets increased, and the current passing through those LEDs alsogets increased. However, at the instant time point of turning off 12B,the voltage over the drain 122 in 12A will be very high, which is aroundthe total number of LED lamps in both light-strings 11A and 11B times3.0V, and, usually, the current in LEDs is 30 mA or higher. Suppose thetotal number of lamps in both 11A and 11B is 30, then, the powerconsumption of the chip will be 30×3.0V×30 mA=2700 mW, which means, theefficiency of a commonly used 7 W LED lighting system is less than 80%.Also, since the power consumption in the chip is 2.7 W, it will requirea higher requirement for chip packaging.

And the light flux of an LED driven by a conventional AC drivingapparatus will get higher following the rising of the supplied powervoltages, which means a relatively large variation in light flux, also,in a conventional AC driving mode for LED, when the voltage is low, onlya part of the LEDs in the LED string will get lit-on, and when thevoltage is high, all LEDs will get lit-on, thus, during a sinusoidalvoltage cycle, part of the LEDs are almost always in an off status,while other part of LEDs get lit-on during only ¼ cycle or even less,therefore, the attenuations of all LEDs are different, resulting in aworse lighting effects after a long time.

Therefore, the prior art needs to be improved and developed.

BRIEF SUMMARY OF THE DISCLOSURE

The technical problems to be solved in the present invention is, aimingat the defects of the prior art, providing an LED driving device fordynamic segment configurations and the LED lighting apparatus thereof,in order to solve the problems in the prior art, including a lowconversion efficiency and a bad lighting effect caused by aninconsistent attenuation of LED lamps.

The technical solution of the present invention to solve the technicalproblems is as follows:

An LED driving device for dynamic segment configurations, connecting toa bridge rectifier, which includes: a first adjustable LED lamp stringunit, a first N-type switch module, at least one adjustable LED lampstring module, at least one P-type switch module, at least one secondN-type switch module, a control logic module, applied to control thefirst adjustable LED lamp string unit, the adjustable LED lamp stringmodule, the P-type switch module, the first N-type switch module and thesecond N-type switch module, as well as a current detection module,applied to detect the output currents from the first and the secondN-type switch modules before feeding back to the control logic module;the adjustable LED lamp string module comprises a second adjustable LEDlamp string unit and a unidirectional conduction unit;

The control logic module outputs control signals, based on the outputvoltage variations from the bridge rectifier, to control the turn-on andturn-off states of the first adjustable LED lamp string unit, theadjustable LED lamp string module, the P-type switch module, the firstN-type switch module and the second N-type switch module, also itadjusts the serial connection and parallel connection states of thefirst and the second adjustable LED lamp string units dynamically.

The LED driving device for dynamic segment configurations, wherein, theP terminal of the second adjustable LED lamp string unit connects to thepositive output terminal of the bridge rectifier, as well as connectingto the negative terminal of the unidirectional conduction unit and the Pterminal of the first adjustable LED lamp string unit through the P-typeswitch module, the N terminal of the second adjustable LED lamp stringunit connects to positive terminal of the unidirectional conductionunit, the N terminal of the second adjustable LED lamp string unitconnects to the current detection module through the second N-typeswitch module, the N terminal of the first adjustable LED lamp stringunit connects to the current detection module through the first N-typeswitch module.

The LED driving device for dynamic segment configurations, wherein, thesecond adjustable LED lamp string unit includes a first LED lamp string,a second LED lamp string and a first P-type switch unit; the first LEDlamp string connects to the second LED lamp string in series, one end ofthe first P-type switch unit connects to the positive terminal of thefirst LED lamp string, the other end of the first P-type switch unitconnects to the negative terminal of the first LED lamp string and thepositive terminal of the second LED lamp string, the control terminal ofthe first P-type switch unit connects to the control logic module, thepositive terminal of the first LED lamp string connects to the positiveoutput terminal of the bridge rectifier, the negative terminal of thesecond LED lamp string connects to the positive terminal of theunidirectional conduction unit.

The LED driving device for dynamic segment configurations, wherein, thesecond adjustable LED lamp string unit includes a first LED lamp string,a second LED lamp string, a third LED lamp string, a first P-type switchunit and a second P-type switch unit; the first LED lamp string, thesecond LED lamp string and the third LED lamp string are connected inseries, one end of the first P-type switch unit connects to the positiveterminal of the first LED lamp string, the other end of the first P-typeswitch unit connects to the negative terminal of the first LED lampstring and the positive terminal of the second LED lamp string, thecontrol terminal of the first P-type switch unit connects to the controllogic module; one end of the second P-type switch unit connects to thepositive terminal of the second LED lamp string, the other end of thesecond P-type switch unit connects to the negative terminal of thesecond LED lamp string and the positive terminal of the third LED lampstring, the control terminal of the second P-type switch unit connectsto the control logic module, the positive terminal of the first LED lampstring connects to the positive output terminal of the bridge rectifier,the negative terminal of the third LED lamp string connects to thepositive terminal of the unidirectional conduction unit.

The LED driving device for dynamic segment configurations, wherein, theunidirectional conduction unit includes a diode, whose anode connects tothe N terminal of the second adjustable LED lamp string unit, while thecathode of the diode connects to the P terminal of the first adjustableLED lamp string unit.

The LED driving device for dynamic segment configurations, wherein, thefirst N-type switch module includes a second MOS transistor, the gate ofthe second MOS transistor connects to the control logic module, thedrain of the second MOS transistor connects to the N terminal of thefirst adjustable LED lamp string unit, and the source of the second MOStransistor gets grounded through the current detection module;

The second N-type switch module includes a third MOS transistor, thegate of the third MOS transistor connects to the control logic module,the drain of the third MOS transistor connects to the N terminal of thesecond adjustable LED lamp string unit, and the source of the third MOStransistor gets grounded through a current detection module;

The LED driving device for dynamic segment configurations, wherein, theP-type switch module includes a controllable current source, JFET, afirst resistor, a Zener diode and a first MOS transistor; thecontrollable current source connects to the control logic module, oneend of the controllable current source connects to the source of theJFET, while the other end gets grounded; the drain of the JFET connectsto the gate of the first MOS transistor, and connects to the source ofthe first MOS transistor through a first resistor, the gate of the JFETgets grounded; the anode of the Zener diode connects to the gate of thefirst MOS transistor, the cathode of the Zener diode connects to thesource of the first MOS transistor; the drain of the first MOStransistor connects to the adjustable LED lamp string module and thefirst adjustable LED lamp string unit, the source of the first MOStransistor connects to the positive output terminal of the bridgerectifier.

The LED driving device for dynamic segment configurations, wherein, thenumber of each of the adjustable LED lamp string module, P-type switchmodule and the second N-type switch module is K, wherein, K is apositive integer;

The control logic module outputs control signals based on the variationsof the output voltages from the bridge rectifier, and controls theturn-on and turn-off states of the first adjustable LED lamp stringunit, K of the adjustable LED lamp string modules, K of the P-typeswitch modules, a first N-type switch module and K of the second N-typeswitch modules, adjusts the parallel and serial connection statesdynamically, of the first adjustable LED lamp string unit and K of thesecond adjustable LED lamp string units, achieves one group ofadjustable LED lamp string units in a number of N connecting in series,before connecting different groups in parallel; wherein, N is a positiveinteger from 1 to K+1.

An LED lighting apparatus, wherein, it includes: a bridge rectifierapplied to rectify the input signals and an LED driving device fordynamic segment configurations, the positive terminal of the bridgerectifier connects to the LED driving device for dynamic segmentconfigurations, while the negative terminal gets grounded.

Comparing to the prior arts, the present invention provides an LEDdriving device for dynamic segment configurations and the LED lightingapparatus thereof, wherein, the control logic module outputs controlsignals, based on the output voltage variations from the bridgerectifier, to control the turn-on and turn-off states of the firstadjustable LED lamp string unit, the adjustable LED lamp string module,P-type switch module, the first N-type switch module and the secondN-type switch module, adjusts the parallel and serial connection statesdynamically, of the first adjustable LED lamp string unit and theadjustable LED lamp string modules. The present invention adopts adynamic configuration technology, making as many as LEDs light up, also,it makes all LEDs' lit-on time the same, thus improves the lightingeffects and utilization rates.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a circuit diagram in the patent of invention with apublication No. CN102196627.

FIG. 2 illustrates a circuit diagram in the patent of invention with apublication No. US 2011/0084619A1.

FIG. 3 illustrates a block diagram of the LED driving device for dynamicsegment configurations as provided in the first preferred embodiment inthe present invention.

FIG. 4 illustrates a circuit diagram of the P-type switch module in theLED driving device for dynamic segment configurations as provided in thefirst preferred embodiment in the present invention.

FIG. 5 illustrates a circuit diagram of an embodiment of the adjustableLED lamp string module in the LED driving device for dynamic segmentconfigurations as provided in the first preferred embodiment in thepresent invention.

FIG. 6 illustrates a circuit diagram of another embodiment of theadjustable LED lamp string module in the LED driving device for dynamicsegment configurations as provided in the first preferred embodiment inthe present invention.

FIG. 7 illustrates a circuit diagram of the unidirectional conductionunit in the adjustable LED lamp string module in the LED driving devicefor dynamic segment configurations as provided in the first preferredembodiment in the present invention.

FIG. 8 illustrates a circuit diagram of the first N-type switch modulein the adjustable LED lamp string module in the LED driving device fordynamic segment configurations as provided in the first preferredembodiment in the present invention.

FIG. 9 illustrates a circuit diagram of the second N-type switch modulein the adjustable LED lamp string module in the LED driving device fordynamic segment configurations as provided in the first preferredembodiment in the present invention.

FIG. 10 illustrates a block diagram of the LED driving device fordynamic segment configurations as provided in the second preferredembodiment in the present invention.

DETAILED DESCRIPTION

The present invention provides an LED driving device for dynamic segmentconfigurations and the LED lighting apparatus thereof, in order to makethe purpose, technical solution and the advantages of the presentinvention clearer and more explicit, further detailed descriptions ofthe present invention are stated here, referencing to the attacheddrawings and some embodiments of the present invention. It should beunderstood that the detailed embodiments of the invention described hereare used to explain the present invention only, instead of limiting thepresent invention.

The LED driving device for dynamic segment configurations, provided bythe present invention, connects to the positive output terminal of thebridge rectifier, applied to dynamically configure the number of lit-onLEDs in the LED subsections, which includes: a first adjustable LED lampstring unit, a first N-type switch module, at least one adjustable LEDlamp string module, at least one P-type switch module, at least onesecond N-type switch module, a control logic module, applied to controlthe functions of the first adjustable LED lamp string unit, theadjustable LED lamp string module, the P-type switch module, the firstN-type switch module and the second N-type switch module, as well as acurrent detection module, applied to detect the output currents from thefirst N-type switch module and the second N-type switch module beforefeeding back to the control logic module; wherein, the adjustable LEDlamp string module comprises a second adjustable LED lamp string unitand a unidirectional conduction unit;

The control logic module outputs control signals, based on the outputvoltage changes from the bridge rectifier, to control the turn-on andturn-off states of the first adjustable LED lamp string unit, theadjustable LED lamp string module, the P-type switch module, the firstN-type switch module and the second N-type switch module, also itadjusts the serial or parallel connection status of the first and thesecond adjustable LED lamp string units dynamically.

Referencing to FIG. 3, which is a block diagram of the LED drivingdevice for dynamic segment configurations as provided in the firstpreferred embodiment in the present invention. Shown as FIG. 3, in theLED driving device for dynamic segment configurations as provided in thepresent embodiment, the number of the first adjustable LED lamp stringunit 210, the first N-type switch module 310, the adjustable LED lampstring module 200 (including the second adjustable LED lamp string unit220 and the unidirectional conduction unit 230), the P-type switchmodule 400, the second N-type switch module 320, the control logicmodule 500 and the current detection module 600 is one only.

The control logic module 500 outputs PEN signals to control the on/offof the P-type switch module 400, and outputs NEN<1-2> signals to controlthe on/off of the first N-type switch module 310 and the second N-typeswitch module 320, thus controls the serial and parallel connectionstates of the first adjustable LED lamp string unit 210 and the secondadjustable LED lamp string units 220 dynamically. The control logicmodule 500 outputs LED_CTL1, LED_CTL2 signals to configure the lit-onLED numbers in the adjustable LED lamp string module 200 and the firstadjustable LED lamp string unit 210, the first end 1 of the currentdetection module 600 connects to the first N-type switch module 310 andthe second N-type switch module 320, the second end 2 of the currentdetection module 600 connects to the control logic module 500, and thethird end 3 of the current detection module 600 gets grounded, appliedto detect the current passing through the first adjustable LED lampstring unit 210 and/or the adjustable LED lamp string module 200, andoutputs the detection results to the control logic module 500, then, thecontrol logic module 500 will back deduce the voltage output from thebridge rectifier, based on the detection results. The control logicmodule 500 may control itself output the according control signals,through control chips and according control software, dynamicallyconfigure the serial or parallel connection status of the firstadjustable LED lamp string unit 210 and the second adjustable LED lampstring unit 220. The current detection module 600 only need to be ableto detect the currents passing through the first N-type switch module310 and the second N-type switch module 320, and feedback to the controllogic module 500, thus the present invention has no restrictions on thecircuit structure of the current detection module 600.

Referencing to FIG. 4 together, the P-type switch module 400 includes acontrollable current source I, JFET (The earliest field effecttransistor (FET) owning a practical structure, which is also known as aPN junction type FET) J1, a first resistor R1, a Zener diode DZ1 and afirst MOS transistor Q1. Wherein, the JFET J1 is a high voltage N-typeJFET, the first MOS transistor Q1 is a high voltage PMOS transistor,wherein, the high voltage resistances of both the high voltage N-typeJFET J1 and the high voltage PMOS transistor are over 311V (that is thepeak voltage output from the bridge rectifier 100).

The controllable current source I connects to the control logic module500, one end of the controllable current source I connects to the sourceof the JFET J1, and the other end of the controllable current source Igets grounded; the drain of the JFET J1 connects to the gate of thefirst MOS transistor Q1, and connects to the source of the first MOStransistor Q1 through the first resistor R1, the gate of the JFET J1gets grounded. The control logic module 500 outputs PEN signals tocontrol the status of the controllable current source I, and thecontrollable current source I provides an “on” current at I_(th) and an“off” current at 0.1×I_(th). The high voltage N-type JFET J1 is alwayson, mainly applied to provide a cascade effect, to ensure the voltage onits source is always below the pinch-off voltage, and to avoid damagingthe controllable current source I due to overvoltage.

The anode of the Zener diode DZ1 connects to the gate of the first MOStransistor Q1, and the cathode of the Zener diode DZ1 connects to thesource of the first MOS transistor Q1; the drain of the first MOStransistor Q1 connects to the adjustable LED lamp string module 200 andthe first adjustable LED lamp string unit 210 (which is marked as −/P inFIG. 4), the source of the first MOS transistor Q2 connects to thepositive output end of the bridge rectifier 100 (marked as + in FIG. 4).

In the P-type switch module 400 as provided in the present embodiment,when the current passes through the first resistor R1, a voltagedifference will be generated between both ends of the first resistor R1,thus, when the current output from the controllable current source I is6, the voltage difference will be sufficient to turn on the high voltagePMOS transistor; and when the current output from the controllablecurrent source I is 0.1×I_(th), the voltage difference will be notenough to turn on the high voltage PMOS transistor, thus the PMOStransistor will be off. The Zener diode DZ1 provides a clamping action,to avoid the damage of either gate or source of the PMOS transistor, dueto overvoltage. The P-type switch module 400 as provided in the presentembodiment achieves the function of controlling the on and off of a highvoltage PMOs transistor through a low voltage control signal.

It should be noted that, in the P-type switch module 400 as provided inthe present embodiment, the JFET J1 may be substituted by otherelectronic elements, including high voltage NMOS transistor, NPN triode,and more. In addition, the turn-off current output from the controllablecurrent source I may be increased, or further decreased, to reduce thestatic power consumptions.

Referencing to FIG. 3 again, in the LED driving device for dynamicsegment configurations as provided in the present invention, theadjustable LED lamp string module 200 includes a second adjustable LEDlamp string unit 220 and a unidirectional conduction unit 230, the Pterminal (i.e., positive) of the second adjustable LED lamp string unit220 connects to the positive output terminal of the bridge rectifier100, and connects to the negative terminal of the unidirectionalconduction unit 230 and the P terminal of the first adjustable LED lampstring unit 210, through the P-type switch module 400, the N terminal(i.e., negative) of the second adjustable LED lamp string unit 220connects to the positive terminal of the unidirectional conduction unit230, and the N terminal of the second adjustable LED lamp string unit220 connects to the current detection module 600, through the secondN-type switch module 320, the N terminal of the first adjustable LEDlamp string unit 210 connects to the current detection module 600,through the first N-type switch module 310.

In the present embodiment, the circuit structure of the secondadjustable LED lamp string unit 220 is the same as that of the firstadjustable LED lamp string unit 210, and both are able to adopt multiplecircuit structures. Shown as FIG. 5, one circuit structure of the secondadjustable LED lamp string unit 220 includes a first LED lamp string M1,a second LED lamp string M2 and a first P-type switch unit 410. Thecircuit structures of the first LED lamp string M1 and the second LEDlamp string M2 are the same; each LED lamp string is composed bymultiple LED lamps connected in series, and the first LED lamp string M1is connected to the second LED lamp string M2 in series.

One end of the first P-type switch unit 410 connects to the positiveterminal of the first LED lamp string M1, and the other end of the firstP-type switch unit 410 connects to the negative terminal of the firstLED lamp string M1 and the positive terminal of the second LED lampstring M2, the control terminal of the first P-type switch unit 410connects to the control logic module 500, the positive terminal of thefirst LED lamp string M1 connects to the positive output terminal of thebridge rectifier 100, the negative terminal of the second LED lampstring M2 connects to the positive terminal of the unidirectionalconduction unit 230.

When the first P-type switch unit 410 is turned on, the first LED lampstring M1 is turned off, when the first P-type switch unit 410 is turnedoff, the first LED lamp string M1 is turned on, thus, it is possible tocontrol the number of lit-on lights in the LED lamp string throughcontrolling the status of the first P-type switch unit 410.

In the present embodiment, the circuit structure of the first P-typeswitch unit 410 is the same as that of the P-type switch module 400, andthe only difference is, the first P-type switch unit 410 adopts anisolated type of low voltage PMOS transistor instead of a high voltagePMOS transistor as used in the P-type switch module 400. Thecharacteristics of an isolated type of low voltage PMOS transistorincludes: 1. the voltage difference between the drain and the source ofthe low voltage PMOS transistor is no less than the sum of the positivevoltages of the first LED lamp string M1, which is connected in parallelto the first P-type switch unit 410; 2. the withstand voltage from thedrain, source and gate to the chip substrate is larger than the highestpower source voltage.

Referencing to FIG. 3 and FIG. 6, which is a circuit diagram of anotherembodiment on the adjustable LED lamp string unit in the LED drivingdevice for dynamic segment configurations as provided in the firstpreferred embodiment in the present invention. The adjustable LED lampstring unit is the first adjustable LED lamp string unit 210 or thesecond adjustable LED lamp string unit 220. Shown as FIG. 6, the secondadjustable LED lamp string unit 220 includes a first LED lamp string M1,a second LED lamp string M2, a third LED lamp string M3, a first P-typeswitch unit 410 and a second P-type switch unit 420. The first LED lampstring M1 and the second LED lamp string M2 and the third LED lampstring M3 are connected in series, one end of the first P-type switchunit connects to the positive terminal of the first LED lamp string, theother end of the first P-type switch unit connects to the negativeterminal of the first LED lamp string and the positive terminal of thesecond LED lamp string, the control terminal of the first P-type switchunit connects to the control logic module; one end of the second P-typeswitch unit 420 connects to the positive terminal of the second LED lampstring M2, the other end of the second P-type switch unit 420 connectsto the negative terminal of the second LED lamp string M2 and thepositive terminal of the third LED lamp string M3, the control terminalof the second P-type switch unit 420 connects to the control logicmodule 500, the positive terminal of the first LED lamp string M1connects to the positive output terminal of the bridge rectifier, thenegative terminal of the third LED lamp string M3 connects to thepositive terminal of the unidirectional conduction unit 230.

The only difference between the another embodiment and the embodiment onthe adjustable LED lamp string unit, is, a group of P-type switch unitand a group of LED lamp string are added to the another embodiment, thusit is possible to adjust the number of lit-on LEDs in the LED lampstring, through the turn-on and turn-off states of the two P-type switchunits, that is, adjusting the minimum positive voltage value of the LEDlamp string to be VF_(min)=VF×M3, the maximum to beVF_(max)=VF×(M1+M2+M3). Further, it is possible to adopt other numbersof the P-type switch units and the LED lamp strings in both the firstadjustable LED lamp string unit 210 and the second adjustable LED lampstring unit 220.

Referencing to both FIG. 3 and FIG. 7 together, in the LED drivingdevice for dynamic segment configurations, the unidirectional conductionunit 230 includes a diode D1, the diode D1 is a high voltage diode(whose withstand voltage is over 311V), and its anode connects to the Nterminal of the second adjustable LED lamp string unit 220, the cathodeof the diode D1 connects to the P terminal of the first adjustable LEDlamp string unit 210.

In the present embodiment, the unidirectional conduction unit 230 worksonly in two states: on and off, during the on state, the voltagedifference between the two ends is expected to be as small as possible,in the off state, the voltage at the negative terminal is expected to belarger than the voltage at the positive terminal without any leakages.Of course, the present invention is possible to adopt otherunidirectional conduction devices having the same functions, such asusing MOS transistors or transistors connecting with diodes instead ofthe diode. The present invention has no restrictions on the electricelements adopted in the unidirectional conduction unit.

Referencing to both FIG. 3 and FIG. 8 together, the first N-type switchmodule 310 includes a second MOS transistor, the gate of the second MOStransistor Q2 connects to the control logic module 500, the drain of thesecond MOS transistor Q2 connects to the N terminal of the firstadjustable LED lamp string unit 210, the source of the second MOStransistor Q2 gets grounded through the current detection module 600.

Accordingly, referencing to both FIG. 3 and FIG. 9 together, the secondN-type switch module 320 includes a third MOS transistor Q3, the gate ofthe third MOS transistor connects to the control logic module 500, thedrain of the third MOS transistor Q3 connects to the N terminal of thesecond adjustable LED lamp string unit 220, the source of the third MOStransistor Q3 get grounded through the current detection module 600.

In the present embodiment, the circuit structures of the first N-typeswitch module 310 and the second N-type switch module 320 are the same.Both the second MOS transistor Q2 and the third MOS transistor Q3 arehigh voltage NMOS transistors, the withstand voltage of the second MOStransistor Q2 is higher than that of the third MOS transistor Q3.

The LED driving device for dynamic segment configurations as provided inthe second preferred embodiment in the present invention is shown inFIG. 10, in the presented second preferred embodiment, the number of theadjustable LED lamp string modules 200, P-type switch modules 400 andthe second N-type switch modules 320 is K, wherein, K is a positiveinteger. In the first preferred embodiment, K is a number equal to 1,while in the second preferred embodiment, the K is a positive integer noless than 2. Shown as FIG. 10, every adjustable LED lamp string module200 connects to a P-type switch module 400 and a second N-type switchmodule 320, the first adjustable LED lamp string unit 210 connects tothe current detection module 600 through the first N-type switch module310. In the embodiment sown in FIG. 10, from left to right, the P-typeswitch module 400 and the second N-type switch module 320 is the first,the second, . . . the K′th in sequence, (shown as the bold numbers 1, 2. . . K in FIG. 10), from upper to lower, the second adjustable LED lampstring unit 220 is the first, the second, . . . the K′th in sequence,(shown as the bold numbers 1, 2 . . . K in FIG. 10).

Since the first adjustable LED lamp string unit 210 is the same as thesecond adjustable LED lamp string unit 220, the second N-type switchmodule 320 is the same as the first N-type switch module 310, for thepurpose of convenient descriptions, both the first adjustable LED lampstring unit 210 and the second adjustable LED lamp string unit 220 arecalled adjustable LED lamp string unit, both the second N-type switchmodule 320 and the first N-type switch module 310 are called N-typeswitch module in the present invention. Therefore, the numbers of boththe adjustable LED lamp string units and the N-type switch modules areK+1, and the N-type switch module is composed by high voltage NMOStransistors, whose withstand voltage decreases in a sequence from thefirst to the (K+1)th.

The control logic module outputs control signals and controls theturn-on and turn-off states of the first adjustable LED lamp stringunit, K of the adjustable LED lamp string modules, K of the P-typeswitch modules, the first N-type switch module and K of the secondN-type switch modules, adjusts dynamically the serial and parallelconnection states of the first adjustable LED lamp string unit and K ofthe second adjustable LED lamp string units, achieves a group ofadjustable LED lamp string in a number of N, then connecting each groupin parallel; wherein, N is a positive integer from 1 to K+1. As shown inFIG. 10, the LED driving device for dynamic segment configurationsprovided in the second preferred embodiment, detects the current in eachN-type switch module through the current detection module 600, and feedsit back to the control logic module 500, then the control logic module500 deduces the voltage output from the bridge rectifier 100, based onthe current value, so as to output signals PEN<1:K>, LED_CTL1-LED_CTLK+1and NEN<1:K+1>, to control the parallel and serial connection states ofeach adjustable LED lamp string, and the numbers of lit-on LEDs in eachadjustable LED lamp string, so as to dynamically configure the number oflit-on LEDs.

Detailed descriptions to the method of dynamical configuration as in thepresent invention are listed below, based on the second preferredembodiment:

When the voltage output from the bridge rectifier 100 is betweenVF_(min) and VF_(max), connecting all adjustable LED lamp string unitsin parallel, now all the LED lamp string are lit-on. The implementationmethod is: turn on all the P-type switch modules 400 (in a number of K,totally) and all the N-type switch modules (in a number of K+1,totally), then all the positive terminals of the unidirectionalconduction units 230 (in a number of K, totally) connect to the currentdetection module 600 through the according N-type switch modules beforegetting grounded, all the negative terminals of the unidirectionalconduction units 230 connect to the output terminal of the 100 throughthe according P-type switch module 400, all the unidirectionalconduction units 230 are in the reverse blocking status, each of theadjustable LED lamp string unit is isolated by the reverse blockingunidirectional conduction unit 230. The P terminals from the secondadjustable LED lamp string unit to the K+1th adjustable LED lamp stringunit are connected to the positive output terminal of the bridgerectifier 100, through according P-type switch modules 400; all the Nterminals of the adjustable LED lamp string units are connecting to thefirst terminal 1 of the current detection module 600, through theaccording N-type switch modules, therefore, all the adjustable LED lampstring units have currents passing through, and all the adjustable LEDlamp string units have lights output.

When the voltage output from the bridge rectifier 100 is betweenVF_(max) and 2VF_(max), connecting every two of the adjustable LED lampstring units in series before connecting in parallel, if the number ofthe adjustable LED lamp string units is not divisible by 2, then theextra one adjustable LED lamp string unit is controlled to be off. Theimplementation method is: the control logic module 500 controls thefirst P-type switch module 400 be off, the second P-type switch module400 be on, the first N-type switch module be off, the second N-typeswitch module be on, then, the first adjustable LED lamp string unit,the first unidirectional conduction unit 230 and the second adjustableLED lamp string unit connect to a point between the output terminal ofthe bridge rectifier 100 and the current detection module 600, whichmakes the first and the second adjustable LED lamp string units belit-on; similarly, controls the third P-type switch module 400 be off,the fourth P-type switch module 400 be on, the third N-type switchmodule be off, the fourth N-type switch module be on, then, the thirdadjustable LED lamp string unit, the third unidirectional conductionunit 230 and the fourth adjustable LED lamp string unit connect to apoint between the output terminal of the bridge rectifier 100 and thecurrent detection module 600, which makes the third and the fourthadjustable LED lamp string units be lit-on; so as on, controls the2N-1th P-type switch module 400 and the 2N-1th N-type switch module beoff, the 2Nth P-type switch module 400 and the 2Nth N-type switch modulebe on, then, makes the 2N-1th adjustable LED lamp string unit, the2N-1th unidirectional conduction unit 230 and the 2N adjustable LED lampstring unit connect to a point between the output terminal of the bridgerectifier 100 and the current detection module 600, and making itlit-on, so as to achieve the adjustable LED lamp string units connectevery two in series into a group, before connecting groups in parallel.

When the voltage output from the bridge rectifier 100 is between2VF_(max) and 3VF_(max), connecting every three of the adjustable LEDlamp string units in series before connecting in parallel. If the numberof the adjustable LED lamp string units is not divisible by 3, then theextra adjustable LED lamp string units are controlled to be off. Theimplementation method is: the control logic module 500 controls thefirst and the second P-type switch module 400 be off, the third P-typeswitch module 400 be on, the first and the second N-type switch modulebe off, the third N-type switch module be on, then, the first to thethird adjustable LED lamp string units, the first and the secondunidirectional conduction unit 230 connect to a point between the outputterminal of the bridge rectifier 100 and the current detection module600, which makes the first to the third adjustable LED lamp string unitsbe lit-on; similarly, controls the fourth and the fifth P-type switchmodules 400 be off, the sixth P-type switch module 400 be on, controlsthe fourth and the fifth N-type switch module be off, the sixth N-typeswitch module be on, then, the fourth to the sixth adjustable LED lampstring unit, the fourth and the fifth unidirectional conduction unit 230connect to a point between the output terminal of the bridge rectifier100 and the current detection module 600, which makes the fourth to thesixth adjustable LED lamp string units be lit-on; so as on, controls the3N-2th, 3N-1th P-type switch module 400 be off, and the 3N-2th, 3N-1thN-type switch module be off, and controls the 3Nth P-type switch module400 and the 3Nth N-type switch module be on, which makes the 3N-2th, the3N-1th, the 3Nth adjustable LED lamp string unit, the 3N-2th, 3N-1thunidirectional conduction unit 230 connect to a point between the outputterminal of the bridge rectifier 100 and the current detection module600, and making the 3N-2th, 3N-1th, 3Nth adjustable LED lamp string unitlit-on.

And so on, therefore, it is possible to achieve the number of Pconnections in series and Q connections in parallel, wherein, P is aninteger between 1 and K+1, Q is an integer between 1 and (K+1)/P.

The embodiments of the present invention also provide an according LEDlighting apparatus, which includes: a bridge rectifier applied torectify the input signals and an LED driving device for dynamic segmentconfigurations, wherein, the positive output terminal of the bridgerectifier connects to the LED driving device for dynamic segmentconfigurations, while the negative output terminal of the bridgerectifier gets grounded. The supplied AC power connects into the bridgerectifier, then gets rectified by the bridge rectifier, before beinginput into the LED driving device for dynamic segment configurations,then, the LED driving device for dynamic segment configurations startsto configure the parallel and serial connection states of eachadjustable LED lamp string unit dynamically, based on the output voltageof the bridge rectifier. Since both the circuit structure and theoperation principle of the LED driving device for dynamic segmentconfigurations have been described in details above, no moredescriptions will be listed here.

Comparing to prior arts, the present invention owns the followingbenefits:

1. A light flux of an LED driven by a conventional AC driving apparatuswill get higher following the rising of supplied power voltages.However, after adopting the LED driving device for dynamic segmentconfigurations as provided in the present invention, when the voltage islow, connects all lights strings in parallel first, then following thevoltage variations, divides all lamps into groups, lamps in each groupare connected in series, and different groups are connected in parallel,so as to light on LED lamps as many as possible, and ensures more lightflux get output. This ensures that, during the whole period of suppliedpower varying, most LED lamps are lit-on, thus the light flux will notchange too much.

2. For a conventional AC driving apparatus for LED, when the voltage islow, only part of the lamps are lit-on, and when the voltage is high,all lamps are lit-on, thus, in a sinusoidal voltage cycle, some of theLED beams are always lit-on, while other part of the LED beams arelit-on only in ¼ cycle or even less, thus the attenuations of all LEDlight beams are different, resulting in a worse lighting effects after along time. However, after adopting the LED driving device for dynamicsegment configurations as provided in the present invention, the lit-ontime is almost the same, which therefore, ensures the lighting effectsover a long period keep the same.

3. After adopting the LED driving device for dynamic segmentconfigurations as provided in the present invention, almost all LEDlamps are lit-on all the time, which improves the utilization of LEDlamps.

It should be understood that, the application of the present inventionis not limited to the examples listed. It will be possible for a personskilled in the art to make modification or replacements according to thedescriptions, which shall all fall within the scope of protection in theappended claims of the present invention.

What is claimed is:
 1. An LED driving device for dynamic segmentconfigurations, connecting to a bridge rectifier, wherein, the LEDdriving device comprises: a first adjustable LED lamp string unit, afirst N-type switch module, at least one adjustable LED lamp stringmodule, at least one P-type switch module, at least one second N-typeswitch module, a control logic module, applied to control the firstadjustable LED lamp string unit, the adjustable LED lamp string module,the P-type switch module, the first N-type switch module and the secondN-type switch module, as well as a current detection module, applied todetect the output currents from the first N-type switch module and thesecond N-type switch module before feeding back to the control logicmodule; the adjustable LED lamp string module comprises a secondadjustable LED lamp string unit and a unidirectional conduction unit;and a control logic module outputs control signals, based on the outputvoltage variations from the bridge rectifier, to control the turn-on andturn-off states of the first adjustable LED lamp string unit, theadjustable LED lamp string module, the P-type switch module, the firstN-type switch module and the second N-type switch module, also itadjusts the serial and parallel connection states of the first and thesecond adjustable LED lamp string units dynamically.
 2. The LED drivingdevice for dynamic segment configurations according to claim 1, wherein,the P terminal of the second adjustable LED lamp string unit connects tothe positive output terminal of the bridge rectifier, as well asconnecting to the negative terminal of the unidirectional conductionunit and the P terminal of the first adjustable LED lamp string unitthrough the P-type switch module, positive terminal of theunidirectional conduction unit, the N terminal of the second adjustableLED lamp string unit connects to the current detection module throughthe second N-type switch module, the N terminal of the first adjustableLED lamp string unit connects to the current detection module throughthe first N-type switch module.
 3. The LED driving device for dynamicsegment configurations according to claim 2, wherein, the secondadjustable LED lamp string unit includes a first LED lamp string, asecond LED lamp string and a first P-type switch unit; the first LEDlamp string connects to the second LED lamp string in series, one end ofthe first P-type switch unit connects to the positive terminal of thefirst LED lamp string, the other end of the first P-type switch unitconnects to the negative terminal of the first LED lamp string and thepositive terminal of the second LED lamp string, the control terminal ofthe first P-type switch unit connects to the control logic module, thepositive terminal of the first LED lamp string connects to the positiveoutput terminal of the bridge rectifier, the negative terminal of thesecond LED lamp string connects to the positive terminal of theunidirectional conduction unit.
 4. The LED driving device for dynamicsegment configurations according to claim 2, wherein, the secondadjustable LED lamp string unit includes a first LED lamp string, asecond LED lamp string, a third LED lamp string, a first P-type switchunit and a second P-type switch unit; the first LED lamp string, thesecond LED lamp string and the third LED lamp string are connected inseries, one end of the first P-type switch unit connects to the positiveterminal of the first LED lamp string, the other end of the first P-typeswitch unit connects to the negative terminal of the first LED lampstring and the positive terminal of the second LED lamp string, thecontrol terminal of the first P-type switch unit connects to the controllogic module; one end of the second P-type switch unit connects to thepositive terminal of the second LED lamp string, the other end of thesecond P-type switch unit connects to the negative terminal of thesecond LED lamp string and the positive terminal of the third LED lampstring, the control terminal of the second P-type switch unit connectsto the control logic module, the positive terminal of the first LED lampstring connects to the positive output terminal of the bridge rectifier,the negative terminal of the third LED lamp string connects to thepositive terminal of the unidirectional conduction unit.
 5. The LEDdriving device for dynamic segment configurations according to claim 3,wherein, the unidirectional conduction unit includes a diode, whoseanode connects to the N terminal of the second adjustable LED lampstring unit, while the cathode of the diode connects to the P terminalof the first adjustable LED lamp string unit.
 6. The LED driving devicefor dynamic segment configurations according to claim 2, wherein, thefirst N-type switch module includes a second MOS transistor, the gate ofthe second MOS transistor connects to the control logic module, thedrain of the second MOS transistor connects to the N terminal of thefirst adjustable LED lamp string unit, and the source of the second MOStransistor gets grounded through the current detection module; and Asecond N-type switch module includes a third MOS transistor, the gate ofthe third MOS transistor connects to the control logic module, the drainof the third MOS transistor connects to the N terminal of the secondadjustable LED lamp string unit, and the source of the third MOStransistor gets grounded through a current detection module.
 7. The LEDdriving device for dynamic segment configurations according to claim 1,wherein, the P-type switch module includes a controllable currentsource, JFET, a first resistor, a Zener diode and a first MOStransistor; the controllable current source connects to the controllogic module, one end of the controllable current source connects to thesource of the JFET, while the other end gets grounded; the drain of theJFET connects to the gate of the first MOS transistor, and the source ofthe first MOS transistor through a first resistor, the gate of the JFETgets grounded; the anode of the Zener diode connects to the gate of thefirst MOS transistor, the cathode of the Zener diode connects to thesource of the first MOS transistor; the drain of the first MOStransistor connects to the adjustable LED lamp string module and thefirst adjustable LED lamp string unit, the source of the first MOStransistor connects to the positive output terminal of the bridgerectifier.
 8. The LED driving device for dynamic segment configurationsaccording to claim 1, wherein, the number of each of the adjustable LEDlamp string module, P-type switch module and the second N-type switchmodule is K, wherein, K is a positive integer; and The control logicmodule outputs control signals based on the variations of the outputvoltages from the bridge rectifier, and controls the turn-on andturn-off states of the first adjustable LED lamp string unit, K of theadjustable LED lamp string modules, K of the P-type switch modules, afirst N-type switch module and K of the second N-type switch modules,adjusts the parallel and serial connection states dynamically, of thefirst adjustable LED lamp string unit and K of the second adjustable LEDlamp string units, achieves one group of adjustable LED lamp stringunits in a number of N connecting in series, before connecting differentgroups in parallel; wherein, N is a positive integer from 1 to K+1. 9.An LED lighting apparatus comprising: a bridge rectifier applied torectify input signals and a LED driving device for dynamic segmentconfigurations, wherein a positive terminal of the bridge rectifierconnects to the LED driving device for dynamic segment configurations,while a negative terminal of the bridge rectifier is grounded.